The present invention relates to a device for treating respiratory deficiency of a patient by additional supply of oxygen fed from a source through at least one duct the end of which opens close to the respiratory passages of the patient to supplement the supply of oxygen inhaled from the surrounding air by the patient.
A variety of devices of this kind are available, and provide the patient with an oxygen enrichment of the air normally breathed in by existing respiratory passages, essentially being the nostrils or else the mouth. One of the most widely applied devices is the oxygen breathing mask which can be fitted to the face and comprises two protrusions allowing oxygen to be supplied to both nostrils of the patient.
However, the devices known until now are fitted with a simple manual valve commonly inserted into the aforesaid duct which is opened by the patient when the apparatus is put in operation. This system has the disadvantage however that the oxygen is fed continuously whereas its supply is useful only during the inhalation stages and represents a total loss during the exhalation stages.
This loss, which is costly per se, represents an even more substantial disadvantage in the case of portable sets for which the capacity of the oxygen source determines the radius of action.
It is an object of the invention to eliminate or minimise the aforesaid shortcomings.